Chris , IMHO you can not go past the Armorscale barrel . It is turned aluminium , with rifling & external thread for the muzzle brake , the Muzzle brake is a beautiful turned brass affair in four pieces , a small brass fret has the collars & a resin mantlet to top it off complete with the missing cast seams ! All scales out well to the available scale drawings . It would be impossible to make a better barrel for it !